Legal

Need help.. Mr. A purchased a plot & on a certain occasion he met his neighbour(Mr. B) since they use to share their financial investments. So Mr. A told Mr. B about the plot so purchsed.. Mr. B got interested & decided to buy one. Mr. B paid all the money but due to some dispute between property dealer the registry could not taked place. also the dealer was short of money so he dicided to give another plot. & Mr. B agreed. but now Mr. B's lawyer is saying that this another plot is not safe (bcoz as per lawyer the plot shown on paper & the plot in real are diff) so he adviced Mr. B to not to accept this plot & ask for money or some another plot. & ALSO HE WARNED Mr. A that he will suit a case against Mr. A too. so my ques is that.. to what extent Mr. A is responsible in this case? how he can prove himself to be innocent??